How to replace each letter in a last name by the consecutive letter in the alphabet? I need this script as a masking tool.
Logic for last name: (a change to b, b change to c, ...., z change to a)
Example: John Doe will become John Epf
Input File: names.txt
John yi
kary Strong
Joe Piazza
So man
This is called Caesar's cipher.
Take a look at how it's done here: https://stackoverflow.com/a/8895517/6664393
You'll have change it a little to allow uppercase characters as well:
def caesar(plaintext, shift):
alphabet_lower = string.ascii_lowercase
alphabet_upper = string.ascii_uppercase
alphabet = alphabet_lower + alphabet_upper
shifted_alphabet_lower = alphabet_lower[shift:] + alphabet_lower[:shift]
shifted_alphabet_upper = alphabet_upper[shift:] + alphabet_upper[:shift]
shifted_alphabet = shifted_alphabet_lower + shifted_alphabet_upper
table = string.maketrans(alphabet, shifted_alphabet)
return plaintext.translate(table)
use shift = 1 to shift by one.
The problem as defined in your question can be solved as follows:
parts = name.split()
parts[1]=''.join([chr((ord(c) - 65 + 1) % 26 + 65)
if ord(c) < 91 else
chr((ord(c) - 97 + 1) % 26 + 97)
for c in parts[1]])
' '.join(parts)
Here, I define the last name as the second word of the string, this of course is a strong assumption, but improving on this is not the main problem in the question.
Shifting the characters is done inside a list comprehension, where each character is processed separately, and first converted to its ASCII code using ord. The ASCII codes of upper case letters are 65-90 (A-Z), and the ASCII codes of lowercase letters are 97-122 (a-z). Therefore, a condition ord(c) < 91 is used to separate the cases. Then, in each case, the ASCII code is converted to a value in the range 0-25, shifted (in the example, incremented by 1), and modulo operation % 26 is used to convert shifted z back into a. The resulting value is then converted back to the proper range for the letter ASCII codes.
